The borad aims of this project continue essentially the same, namely to investigate the various factors that govern the natre of the folding, or conformation, taken up by a protein chaan which determines its biologcal activity, in relation to the various componens of its primary structure, namely its amino acid sequence. These studies would ultimately lead to the possibility of the prediction of the conformation of a polypeptide chain, given the sequence of residuessin it. One of the aims of the continued project would be to estimate the accuracy of the potential functions adopted for this purpose and to obtain more accurate functions by comparing theory and observations (x-ray, NMR, etc.) in various ssmple systems of increasing complexity. In particular, the conformation of peptides having mixed L and D amino acids will be studied, with special reference to their application to the case of peptide antibiotics. The structure of collagen, whih has been one o the main fields of study of the principal investigator, will be refined in order to explain the biological functions of collagen. An additional new problem to be studied will be the mathematical technique of reconstruction of a three-dimensional object from its transmission shadowgraphs. This has wide application in medical radiology and in the study of viruses and other objects by electron microscopy. The conformational studies would ulttmately lead to the prediction of the structure of proteins, enzymes, and antibiotics in relation to their biological activity.